Primitive Technology
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Primitive Technology: Re-smelting previously made iron
🕑 Added 2025-04-03 21:32:30 +0000 UTCI took the iron I already smelted and re- smelted it. The iron was old and rusty from forging experiments. Iron oxidises faster when in the forge due to the hot and oxidising conditions. So I tried smelting it again to turn the rust back into iron. The first attempt involved charging the iron into a furnace in a single charge. The results were mixed, the iron was in separated pieces though the iron was softer and could be slightly cold forged. Next the iron was included in an iron smelt with fresh, roasted ore. 3 charges of ore were charged, then the scrap iron and then another 3 charges of ore. The result was cleaner but the iron was still in separate pieces. Next, an attempt was made to consolidate the iron in a forge. Bricks were taken off the furnace to reduce its height, to form a forge. The iron was charged into the forge and heated in front of the blast to consolidate it. The iron came together a bit but was still in separate bits. The iron was softer and more malleable though. Finally, the iron was put in a crucible with iron ore to decarburise it further. The iron was heated and it became absorbed into the slag. Nearly all of the iron was lost as oxide. I learnt some things from this project. One of the difficulties was not having the iron in one piece as the small pieces of iron tends to get lost in the coals. Next time, I'll likely try a crucible (without iron oxide in it) just to consolidate the freshly made cast iron prills. Once the iron is in one piece, I'll attempt to decarburise it and forge it with light hammer blows.
Much appreciated.
Comments
Primitive Technology
Thanks Amy. I'll keep it in mind. When I can find some type of flour I'll make an oven to make bread in.
Amy Tobol
That was a nice firemaking closeup, thanks. I kinda want to see you make a pizza oven.
Primitive Technology
Hi Steve, The fly wheel was a bit heavy and was wearing out the rotor. I made a thicker rotor to hold the weight but then it wouldn't fit through the hole in the fly wheel and I didn't have time to make and fire a new one. The fly wheel is an ok addition and I might try it again later, possibly by making a fly wheel/impellor combination from clay (a clay disc with raised fins). As for the air gap, yes I've left an air gap before with the previous intermittent blower design. It seems to work about the same. I'm concerned that the blower is low in pressure as it is and so seal the gap as a rule. Leaving an air gap would indeed increase air volume but at the expense of pressure, possibly meaning that the air wouldn't penetrate as far into the fuel bed. I could try it again during a smelt and see if it makes a difference in yield, I'll be doing more smelts soon. Much appreciated.
Steve Maynard
Hey John, Cathartic as always :) Few Qs I thought you had put a flywheel on the blower? Also have you thought of not sealing the joint between the blower and the inlet funnel to see if it draws in more air? Hope the recent deluge we've had in QLD hasn't affected you too much.
